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Computer Modeling in Engineering & Sciences 2024年第5期139卷 1583-1612页

作者： Sergiy Reutskiy Yuhui Zhang Jun Lu Ciren Pubu A.Pidhornyi institute of Mechanical Engineering Problems of NAS of Ukraine Kharkiv61046Ukraine College of mechanics and materials Hohai UniversityNanjing211100China Nanjing Hydraulic Research institute Nanjing210029China Shigatse Everest Urban Investment and Development Group Co Ltd.857000China

This paper presents an efficient numerical technique for solving multi-term linear systems of fractional ordinary differential equations(FODEs)which have been widely used in modeling various phenomena in engineering and *** approximate solution of the system is sought in the formof the finite series over the Müntz *** using the collocation procedure in the time interval,one gets the linear algebraic system for the coefficient of the expansion which can be easily solved numerically by a standard *** technique also serves as the basis for solving the time-fractional partial differential equations(PDEs).The modified radial basis functions are used for spatial approximation of the *** collocation in the solution domain transforms the equation into a system of fractional ordinary differential equations similar to the one mentioned *** examples have verified the performance of the proposed novel technique with high accuracy and efficiency.

关键词： System of FODEs numerical solution Müntz polynomial basis time fractional PDE BSM collocation method

Optimizing profile line interval for enhanced accuracy in rock joint morphology and shear strength assessments

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International Journal of Mining Science and Technology 2024年第5期34卷 587-608页

作者： Leibo Song Quan Jiang Shigui Du Jiamin Song Gang Wang Yanting Gu Xingkai Wang Jinzhong Wu School of Civil Engineering Shaoxing UniversityShaoxing 312000China Key Laboratory of Rock mechanics and Geohazards of Zhejiang Province Shaoxing UniversityShaoxing 312000China State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan 430071China institute of Rock mechanics Ningbo UniversityNingbo 315211China

2D profile lines play a critical role in cost-effectively evaluating rock joint properties and shear ***, the interval(ΔI_(L)) between these lines significantly impacts roughness and shear strength assessments. A detailed study of 45 joint samples using four statistical measures across 500 different ΔI_(L)values identified a clear line interval effect with two stages: stable and *** statistical analysis showed a linear relationship between the error bounds of four parameters,shear strength evaluation, and their corresponding maximum ΔI_(L)values, where the gradient k of this linear relationship was influenced by the basic friction angle and normal stress. Accounting for these factors,lower-limit linear models were employed to determine the optimal ΔI_(L)values that met error tolerances(1%–10%) for all metrics and shear strength. The study also explored the consistent size effect on joints regardless of ΔI_(L)changes, revealing three types of size effects based on morphological ***, larger joints required generally higher ΔI_(L)to maintain the predefined error limits, suggesting an increased interval for large joint analyses. Consequently, this research provides a basis for determining the optimal ΔI_(L), improving accuracy in 2D profile line assessments of joint characteristics.

关键词： Rock joint Roughness Shear strength Size effect Profile line interval effect

Simultaneous transmission of time-frequency and data with co-amplification over urban fiber links

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Chinese Optics Letters 2024年第1期22卷 28-33页

作者：操前童周刘雷王家亮应康庞拂飞桂有珍 Key Laboratory of Specialty Fiber Optics and Optical Access Networks School of Communication and Information EngineeringShanghai UniversityShanghai 200444China Key Laboratory for Quantum Optics Shanghai Institute of Optics and Fine MechanicsChinese Academy of SciencesShanghai 201800China Key Laboratory of Space Laser Communication and Detection Technology Shanghai Institute of Optics and Fine MechanicsChinese Academy of SciencesShanghai 201800China Center of materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China

We demonstrate a simultaneous transmission of time-frequency and data over a 160-km urban business network in *** signals are transmitted through a cascaded optical link consisting of 48 km and 32 km,which are connected by an optical *** metrological signals are inserted into the communication network using dense wavelength division *** influence of the interference between different signals has been *** experimental results demonstrate that the radio frequency(RF)instability can reach 2.1×10^(-14)at 1 s and 2.3×10^(-17)at 10,000 s,and the time interval transfer of one pulse per second(1 PPS)signal with less than 10 ps at 1 s is *** work paves the way for the widespread dissemination of ultra-stable time and frequency signals over the communication networks.

关键词： simultaneous transmission radio frequency transfer communication network wavelength multiplexing

Angle measurement of pulsars based on spatially modulated X-ray intensity correlation

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Chinese Optics Letters 2024年第4期22卷 106-111页

作者：汪德喻虹谈志杰陆荣华韩申生 Key Laboratory of Quantum Optics Shanghai Institute of Optics and Fine MechanicsChinese Academy of SciencesShanghai 201800China Center of materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China Hangzhou institute for Advanced Study University of Chinese Academy of SciencesHangzhou 310024China

High-precision angle measurement of pulsars is critical for realizing pulsar *** to visible light and radio waves,the wavelength of X-rays is incredibly short,which provides the possibility of achieving better spatial ***,due to the lack of applicable X-ray apparatus,extracting the angle information of pulsars through conventional X-ray methods is ***,we propose an approach of pulsar angle measurement based on spatially modulated X-ray intensity correlation(SMXIC),in which the angle information is obtained by measuring the spatial intensity correlation between two radiation *** theoretical model for this method has been established,and a proof-of-concept experiment was carried *** SMXIC measurement of observing angles has been demonstrated,and the experimental results are consistent with the theoretical *** potential of this method in future applications is discussed,and theoretically,the angular measurement at the level of micro-arcsecond can be *** sphere of pulsar navigation may benefit from our fresh insights.

关键词： pulsar measurement X-ray measurement intensity correlation spatial modulation

Proton-neutron symplectic model description of ^(106)Cd

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Chinese Physics C 2024年第3期48卷 169-179页

作者： H.G.Ganev Joint institute for Nuclear Research DubnaRussia institute of mechanics Bulgarian Academy of SciencesSofiaBulgaria

In this study,a microscopic shell-model description of the low-lying collective states in the weakly deformed nucleus ^(106)Cd within the recently proposed microscopic version of the Bohr-Mottelson model is provided.A good description of the excitation energies of the lowest ground,γ,andβquasibands is obtained without the adjustable kinetic energy ***,γdegrees of freedom are shown to play a crucial role in the description of spectroscopy of this nucleus.A modified SU(3)SU(3)preserving high-order interaction is used to produce aγ-unstable type of odd-even staggering,observed experimentally between the states of the quasi-γ*** current approach enables the characterization of observed intraband and interband quadrupole *** findings of this study propose an alternative interpretation of the fundamental question regarding the nature of low-energy vibrations,as well as the emergence of deformation and collectivity in weakly deformed atomic nuclei.

关键词： shell-model version of the Bohr-Mottelson model proton-neutron symplectic model Sp(12,R)dynamical algebra quadrupole dynamics

Modeling of Leachate Propagation in a Municipal Solid Waste Landfill Foundation

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Fluid Dynamics & materials Processing 2024年第6期20卷 1407-1424页

作者： Nadezhda Zubova Andrey Ivantsov institute of Continuous Media mechanics of the Ural Branch Russian Academy of SciencePerm614013Russia

The study deals with the numerical modeling of leachate distribution in the porous medium located under a municipal solid waste disposal landfill(MSWLF).The considered three-layer system is based on geological data obtained from field *** simplicity,the problem is investigated by assuming a two-component ***,the heat produced by landfills due to biological and chemical processes and the thermal diffusion mechanism contributing to pollution transport are taken into *** numerical modeling of the propagation of leachate in the considered layered porous medium is implemented for parameters corresponding to natural soil and for the case where disruption of the porous medium structure is due to cracks formation or *** latter is accompanied by an increase in rock *** this case,the emergence of multi-vortex flow in the layer of high permeability is observed to substantially influence the bottom layers and cause intensification of the leachate *** effects should be taken into account when estimating the parameters and properties of materials required for the construction of solid waste disposal facilities.

关键词： Three-layer porous medium binary mixture diffusion thermal diffusion

High-performance broadband photodetector based on PtSe2/MoS2 heterojunction from visible to near-infrared region

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Science China(Information Sciences) 2024年第3期67卷 263-270页

作者： Bin WANG Jian YUAN Mengqi CHE Mingxiu LIU Yuting ZOU Junru AN Fan TAN Yaru SHI Nan ZHANG Liujian QI Shaojuan LI State Key Laboratory of Luminescence and Applications Changchun Institute of OpticsFine Mechanics and PhysicsChinese Academy of Sciences University of Chinese Academy of Sciences State Key Laboratory of Applied Optics Changchun Institute of OpticsFine Mechanics and PhysicsChinese Academy of Sciences School of Physics and Electronic Information Huaibei Normal University

Broadband photodetectors based on narrow bandgap 2D materials have garnered considerable interest for application in the field of optoelectronic devices. However, their large dark current hinders device performance. In this work, a PtSe2/MoS2heterojunction was fabricated for a broadband photodetector operating within the range of visible to near-infrared. The device exhibited suppressed dark currents with a high rectification ratio of 104. The built-in electric field of the heterojunction promoted carrier separation effectively, and the device achieved excellent photoelectric performance with responsivities of 1.7 × 103,27.52, and 21 mA/W at 635, 785, and 1550 nm wavelengths, respectively. Moreover, the specific detectivities(D*) were 2.2 × 1013Jones(635 nm), 3.55 × 1011Jones(785 nm), and 2.72 × 108Jones(1550 nm). The device demonstrated a rise/fall time of 131/241 μs under 1550 nm laser illumination. Visible and near-infrared imaging detection was also demonstrated based on the heterojunction device at room temperature. This work sheds light on the remarkable potential of PtSe2/MoS2heterojunctions in the domain of high-performance broadband photodetectors.

关键词： photodetector PtSe$_{2}$/MoS$_{2}$ heterojunction visible to near infrared high performance

A Subdivision-Based Combined Shape and Topology Optimization in Acoustics

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Computer Modeling in Engineering & Sciences 2024年第4期139卷 847-872页

作者： Chuang Lu Leilei Chen Jinling Luo Haibo Chen CAS Key Laboratory of Mechanical Behavior and Design of materials Department of Modern MechanicsUniversity of Science and Technology of ChinaHefei230027China College of Intelligent Construction Wuchang University of TechnologyWuhan430223China Henan International Joint Laboratory of Structural mechanics and Computational Simulation School of Architecture and EngineeringHuanghuai UniversityZhumadian463000China Beijing Aerospace Technology institute Beijing100074China

We propose a combined shape and topology optimization approach in this research for 3D acoustics by using the isogeometric boundary element method with subdivision *** existing structural optimization methods mainly contain shape and topology schemes,with the former changing the surface geometric profile of the structure and the latter changing thematerial distribution topology or hole topology of the *** the present acoustic performance optimization,the coordinates of the control points in the subdivision surfaces fine mesh are selected as the shape design parameters of the structure,the artificial density of the sound absorbing material covered on the structure surface is set as the topology design parameter,and the combined topology and shape optimization approach is established through the sound field analysis of the subdivision surfaces boundary element method as a *** topology and shape sensitivities of the approach are calculated using the adjoint variable method,which ensures the efficiency of the *** geometric jaggedness and material distribution discontinuities that appear in the optimization process are overcome to a certain degree by the multiresolution method and solid isotropic material with *** examples are given to validate the effectiveness of the presented optimization approach.

关键词： Subdivision surfaces boundary element method topology optimization shape optimization combined optimization

Correlating dynamic relaxation and viscoelasticity in metallic glasses

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Science China(Physics,mechanics & Astronomy) 2024年第5期67卷 81-90页

作者： GuangHui Xing Qi Hao Fan Zhu Yun-Jiang Wang Yong Yang Hidemi Kato Eloi Pineda Si Lan JiChao Qiao School of mechanics Civil Engineering and ArchitectureNorthwestern Polytechnical UniversityXi'an 710072China State Key Laboratory of Nonlinear mechanics Institute of MechanicsChinese Academy of SciencesBeijing 100190China School of Engineering Science University of Chinese Academy of SciencesBeijing 100049China Department of Mechanical Engineering College of EngineeringCity University of Hong KongHong Kong 999077China Department of materials Science and Engineering College of EngineeringCity University of Hong KongHong Kong 999077China institute for materials Research Tohoku UniversitySendai 980-8577Japan Department of Physics Institute of Energy TechnologiesUniversitat Politècnica de CatalunyaBarceona 9Spain School of Material Science and Engineering Herbert Gleiter Institute of NanoscienceNanjing University of Science and Technology.Nanjing 210094China State Key Laboratory of Clean and Efficient Turbomachinery Power Equipment Northwestern Polytechnical UniversityXi'an 710072China

Relaxation dynamics,essential for the structural evolution of non-equilibrium systems like glassy materials,remain ***,we explore relaxation dynamics and viscoelastic properties in three types of metallic glasses with distinctβrelaxation *** systems with significantβrelaxation,stress relaxation and creep experiments reveal a transition from two-step to one-step relaxation with rising ***,such a phenomenon is absent in systems with weakerβ*** model the two-step relaxation process using a double Kohlrausch-Williams-Watts equation,and the obtained relaxation times elegantly adhere to the Arrhenius *** combining fitted activation energies with theoretical analysis,we conclusively attribute these relaxation processes toβrelaxation andαrelaxation,***,we analyze the relaxation time spectra of two processes and establish a comprehensive picture linking dynamic relaxation with *** study provides new strategies for probing the complex relaxation behaviors of glasses from the perspective of viscoelasticity.

关键词： creep relaxation glasses

Continuous-wave operation of 1550 nm low-threshold triple-lattice photonic-crystal surface-emitting lasers

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Light(Science & Applications) 2024年第3期13卷 446-453页

作者： Ziye Wang Xia Liu Pinyao Wang Huanyu Lu Bo Meng Wei Zhang Lijie Wang Yanjing Wang Cunzhu Tong State Key Laboratory of Luminescence and Applications Changchun Institute of OpticsFine Mechanics and PhysicsChinese Academy of SciencesChangchun 130033China Center of materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China Central Research institute Planning Dept 2012 LabsHuawei Technologies Company Ltd.Shenzhen 518129China

Benefitting from narrow beam divergence,photonic crystal surface-emitting lasers are expected to play an essential role in the ever-growing fields of optical communication and light detection and *** operating with 1.55μm wavelengths have attracted particular attention due to their minimum fiber loss and high eye-safe ***,high interband absorption significantly decreases their performance at this 1.55μm ***,stronger optical feedback is needed to reduce their threshold and thus improve the output *** this goal,photonic-crystal resonators with deep holes and high dielectric contrast are often ***,the relevant techniques for high-contrast photonic crystals inevitably complicate fabrication and reduce the final *** this paper,we demonstrate the first continuous-wave operation of 1.55μm photonic-crystal surface-emitting lasers by using a‘triple-lattice photonic-crystal resonator’,which superimposes three lattice point groups to increase the strength of in-plane optical *** this geometry,the in-plane 180°coupling can be enhanced threefold compared to the normal single-lattice *** theoretical and experimental investigations demonstrate the much lower threshold current density of this structure compared to‘single-lattice’and‘double-lattice’photonic-crystal resonators,verifying our design *** findings provide a new strategy for photonic crystal laser miniaturization,which is crucial for realizing their use in future high-speed applications.

关键词： resonator crystal lattice